You have it right:

IMA - integrated motor assist, a system that couples a single, electric motor to an ICE
HSD - hybrid synergy drive, the Toyota dual-motor, planetary gear system

The IMA electric motor provides low-end torque to enhance the startup and low-speed performance of the engine. The HSD uses one motor for the eCVT and the second, a significantly larger motor, for low-end torque, EV operation and regenerative braking. But the HSD requires a current flow to the eCVT motor to get power from the ICE.

In theory, a clutch might 'lock-up' the smaller, eCVT motor of the HSD and improve highway performance. The GM hybrid transmission may perform this experiment.

Bob Wilson

Operation Iraqi Oil Freedom:

Automatic, stock, project car.

My other 1500 cc car:

Automatic, stock, backup car.
Free speech, dialog and knowledge thrives without the poison of SPAM.

My bad. Thought about it a couple hours after I wrote it. Someone stopped in my office to discuss Civic Hybrids and my multi-tasking abilities flew out the window. I typed IMA because we were talking about IMA. I thought I should've gone back to change it, but moved on to other things. (Things I actually get paid for ).

My point still stands, though. The HSD in its current design does not scale up to what the Tundra would need to be a hybrid with credible towing and hauling capability. How long it takes Toyota to correct that depends on how important they think it is to have Tundra and Sequoia hybrids in their portfolio. It will take money and time.

Peace,

James

I am NOT the official voice of GM with respect to Hybrid issues

I am NOT the official voice of GM with respect to Hybrid issues

I am NOT the official voice of GM with respect to Hybrid issues

I've been wondering about the Toyota HiHy and Lexus hybrids. My understanding is the Lexus has a 3,500 pound towing capability. This 1.5 ton capability puts equal to #8, the low end of Edmond's "Top 10 Vehicles for Towing" and enough for a bass boat. Toyota doesn't recommend it for "off road use" but I'm wondering about boat ramps?

At highway speeds, it would be nice to eliminate the motor-to-motor current. Clutching the eCVT motor should be enough if the ICE and gearing allows it.

Bob Wilson

Operation Iraqi Oil Freedom:

Automatic, stock, project car.

My other 1500 cc car:

Automatic, stock, backup car.
Free speech, dialog and knowledge thrives without the poison of SPAM.

I guess the problem is scaling is why Honda hasn't hybridized anything bigger than an Accord. You get a lot of bang for the buck out of the Insight and HCH, and potentially some good efficiency out of a HAH (if only they had used an i4 instead of a v6). I've read in the rumor blogs that Honda's mystery hybrid for 2009 is going to be midway in size between the HCH and Insight.

This doesn't mean IMA is a *bad* product. It's great for what it's designed for.

Likewise, by that same token, I suppose 2-mode would be wasted on a Chevy Aveo.

I often use ratios of MGs to ICE and the Accord was, way down on the scale. If the Accord MG was closer to 40-50 HP, it would have made more sense. The key is making sure the MG has enough low-end torque to allow the ICE to be optimized for high-speed operation.

Bob Wilson

Operation Iraqi Oil Freedom:

Automatic, stock, project car.

My other 1500 cc car:

Automatic, stock, backup car.
Free speech, dialog and knowledge thrives without the poison of SPAM.

The limitations of the IMA is one reason Honda has announced that it is going Diesel with its big vehicles-Odyssey,Pilot and I guess Ridgeline. I guess they are selling more Ridgelines, but they missed the boat with the 5 ft bed.They need at least 5'6"-like the CC Chevy and Titan to be able to stuff MC and such in the bed,and to be able to hang 4x8 plywood and 2x4x92' studs in the bed .The bed is just too short. 6 feet long with 48" between the wheelwells would make it a much better truck.They also need to figure a way to put a cap on the bed.Maybe some sort of flexible/expandable gasket between the bed and cap.The gasket would keep it sealed when the vehicle flexed and twisted.
Around here-New Orleans- you can get some bargains on Chevy 1500 CC- shortbed $18,995 with the 4.8 and $19995 with the 5.3 with some sort of tow pk.This is well under even Dodge's price with their "not the hemi" V-8. Too bad they don't offer a 4 cyl version of the latest Duramax. It makes 360 hp-650 lb-ft- half of that is more than enough for a light duty pickup.With what I expect will be improved aerodynamics of the 2007 1/2 ton, a little diesel could get 23-25 mpg hy(especially with the new 6 speed if it makes it to pickups)
Anyone who remembers 1979-80 remembers we-USA- will give up performance(and size) for FE. It would be nice to be able to keep the utility of a pickup, but still get decent mpg.Most pickup owners don't need as much pickup as we have-Honda was right in that respect- but we do need the ability to haul bulky objects-sofas,chairs, etc.We need a new class of 1/2 ton "light" pickups that gives up tow capability-maybe 5000lbs max-and acceleration but retains the bed size and passenger area-4 cyl diesels with lighter wt suspensions etc and max payloads of 1100 lbs(counting people). The current midsized Tacoma,Frontier are close, but have too little bed width, and not enough backseat.They could also get by with the 4 cyls.Thanks.Charlie